Re: GLR #40's origins??

Interesting challenge. The IRCA had taken over the Guatemala Railway Company in 1912, and it is unclear why Best's roster would have shown a 1920 acquisition as being a Guatemala Railway engine. And then the plot thickens further.
In looking at the IRCA annual reports, the 1921 report shows "3 Baldwin Locomotives No. 50, No. 51 and No. 54" having been added to the equipment of the SALVADOR Division of IRCA. However the same report shows accounts being kept seperately for the Guatemala Railway, Guatemala Central Railroad, Occidental Railroad, Ocos Railroad, and Salvador Line, all part of IRCA. In going back and looking at the 1920 annual report, it also mentions the No. 50 having been recieved by the Salvador division. The fact that the 50 shows up in the two years is probably related to a 9/20 month of manufacture, so it probably showed in Central American around the end of the year.
An obvious question is why was an engine that appears to have gone directly to the Salvador Division of the IRCA given a Guatemala Railway number?
At this point I am reduced to speculation. It seems pretty clear from the annual reports that the IRCA kept seperate books for a number of predecessor roads, but why they did this is unclear. But it is certainly possible that any of the roads mentioned could have been the purchasing road for accounting or financing reasons. And the IRCA did not do a system wide renumbering until 1928, so prior to that the situation in terms of ownership, location, and road number is a bit unclear.
Minor Keith, president of the IRCA was also president of United Fruit. So that is another possibility, although in general United Fruit and IRCA were very seperate entities until the 1930's when United Fruit acquired effective control of IRCA, and did become IRCA's purchasing agent.
I was hoping the builders numbers would solve the puzzle for you, but I guess not.
Interesting puzzle.
John West